Divergence

Divergence is used to allow the existence of Equestrian Revelations in the first place, and allows it to exist outside of the offical, and canon, FiM Universe.

Officially the divergence only exists story-wise, as universe-wise the Equestrian Revelations universe, is already divergent

Differences
Below are the main differences between EQR, and MLP:FiM: There are other differences within the universe of Equestrian Revelations, but they are set to be revealed as each chapter goes on.
 * Presence of Humans - Humans canonically exist on Equis, abeit are slightly different from Earth Humans.
 * Lack of "Childish Themes" - Events, creatures, or other objects that are seen as too fantastical or childish, are removed, or changed (Fruit Bats resembling Fruit are redesigned to look like traditional fruit bats, but with algae colored growths on fur, "Vampire" equivilents no longer suck out, and rot vegetation, but act as traditional vampire bats, the manticore only being agressive due to having a splinter is changed to be an animalistic predator that is defensive against MOST non-prey threats, among other examples)
 * Presence of Adult Themes - Equestrian Revelations retcons chunks of the G-PG Audience Rules, and as such violence, gore, nihilism, philisophical themes, questionable ethics, grey morality, politcs, hatred, religion, sexual themes, depression, mental, racism, harsh language, suicide, drugs, alchohol, illegal activities, etc are main themes within Equestrian Revelations, and as such are NOT SUITABLE for Children under the age of 16-18 (Depending on Location, and maturity)
 * Less Black and White - Yes, an extention of point three, in this universe, Celestia is shown as more of a tyrant (but is still mostly the same) and a lot darker, Dark Arts are committed by the corrupt, and reckless, and Crime is everywhere. Brutus himself is an example of heavy shade of grey, commiting violence, and corruption in an effort to curbstomp crime in his new home. Having a less black and white world, allows for depth, contrast and character development.
 * Some Saipent creatures have been changed physically - All Ponies, Zebras, and certain other species, are semi-anthromorphic, in the sense that they are bipedal, have smaller, more human-like eyes have horse-like hands (although fingers are more claw like) however they (mostly) don't wear clothes, nor have visible sexual organs (except nipples, otherwise being reptile like) aswell as being built similarly to humans, at least in terms of their skeleton (Note: the Ponies/Zebras/etc in EQR do not have breasts, human penis, vaginas, etc, this will be adressed once, from the protagonists POV early on. Otherwise they are visually identical)
 * Retconned Map - Equestrian Revelations map is different from the canonical MLP:FiM universe's map, but the changes are yet to be revealed.